An algorithm is a set of step-by-step instructions or rules that describe, sequentially, how to achieve a task. It is made up of three basic building blocks: sequencing, selection, and iteration.
An algorithm is used for solving or decoding a problem or performing a calculation. They are widely used throughout all areas of technology.
Some features of algorithms are: they have well-defined inputs and outputs, are precise and detailed, and must terminate after a limited number of steps. Algorithms in social networks are the set of programming rules that will cause a post to be shown a lot or a little on a social network (like instagram).